There has been known a gas supply device that temporarily stores gas supplied from a hydrogen producing device and supplies the stored gas to a gas dispenser as disclosed in Patent Literature 1 described below. Specifically, in the gas supply device of this type, a hydrogen compressor and an accumulator are provided in a pipe. The gas led in from the hydrogen producing device is compressed by the hydrogen compressor, and the gas compressed by the hydrogen compressor is stored in the accumulator. The gas stored in the accumulator is supplied to the dispenser according to a pressure difference between a gas pressure in the accumulator and a gas pressure on the dispenser side (differential pressure filling operation). Therefore, during the differential pressure filling operation, the gas pressure in the accumulator gradually drops. If the gas pressure in the accumulator is low after the differential pressure filling operation, the gas pressure in the accumulator can be recovered by performing storing operation.
There are the following problems in the configuration for performing the storing operation after the differential pressure filling operation to recover the gas pressure in the accumulator. When a supply command from the dispenser is frequently issued or when the number of accumulators is small, the gas in the accumulator is consumed in a short period. Since the gas pressure in the accumulator greatly drops, it takes time to return the gas pressure in the accumulator to a set pressure. Hydrogen filling in a vehicle cannot be quickly resumed.